This is a simple hyperlink control that can be plugged into any dialog. There are already
a few examples of this in circulation (PJ Naughter, and one from Paul DiLascia from MSJ)
but none had all the features that I wanted. I have used the GotoURL function by Stuart
Patterson in the Aug 97 WDJ. It is more robust than a simple ShellExecute, and I have
modified it to be a little more Unicode friendly.

The hyperlink is initially coloured blue, but changes colour when the cursor
is over it, and after the user has clicked on it. The cursor that appears when
the mouse pointer is over the link can easily be set using CHyperLink::SetLinkCursor,
as can the link colours and underlining. The default cursor is a small pointing
hand (cursor #106 from the winhlp32.exe file - Thanks to Paul DiLascia of MSJ for
that one). There is also a tooltip for the link that dispalys the underlying URL
of the control.

The link has three underline modes which are set using CHyperLink::SetUnderline:

CHyperLink::ulHover - Underline appears when cursor is over link

CHyperLink::ulNone - No underline

CHyperLinkulAlways - Link is always underlined

To use the hyperlink control, just create a static control (eg IDC_HYPERLINK)
and attach it to a member variable of type CHyperLink. The URL for the link is
taken as the caption of the static control unless otherwise specified. If no
caption for the control is specified then it is set as the URL. If neither exists,
then a debug assertion occurs.

The control can auto-size itself to fit the size of the caption (to preserve
a true hyperlink look and feel). The resizing will honour the SS_CENTERIMAGE,
SS_LEFT, SS_RIGHT and SS_CENTER flags.

The control is very simple. The button click and colour notifications are
handled by the control, and appropriate fonts and colours selected according
to the state of the link. The only tricky bit is handling the button click.
In order to do this the static control must have the SS_NOTIFY bit set and
a ON_CONTROL_REFLECT handler for the STN_CLICKED message is installed.

To actually follow the link, ShellExecute is called to open the URL,
but if this fails, then the registry is examined in order to find a likely
candidate for .htm files. If one is found then this it is launched with the
hope that it can handle the URL string supplied. In any case, an error message
is displayed on failure.

Note on SetColour: This allows
the unvisited/visited and hover colours to be specifed. If the Hover colour (the
colour the link appears when the cursor is over it) is -1, then the system
highlight colour is used.

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About the Author

Chris is the Co-founder, Administrator, Architect, Chief Editor and Shameless Hack who wrote and runs The Code Project. He's been programming since 1988 while pretending to be, in various guises, an astrophysicist, mathematician, physicist, hydrologist, geomorphologist, defence intelligence researcher and then, when all that got a bit rough on the nerves, a web developer. He is a Microsoft Visual C++ MVP both globally and for Canada locally.

His programming experience includes C/C++, C#, SQL, MFC, ASP, ASP.NET, and far, far too much FORTRAN. He has worked on PocketPCs, AIX mainframes, Sun workstations, and a CRAY YMP C90 behemoth but finds notebooks take up less desk space.

He dodges, he weaves, and he never gets enough sleep. He is kind to small animals.

Chris was born and bred in Australia but splits his time between Toronto and Melbourne, depending on the weather. For relaxation he is into road cycling, snowboarding, rock climbing, and storm chasing.